Regulating transformer



June 17. 192

Fjgrz E. POIRSON REGULATXNG TRANSFORMER Filed Aug; 26. 1921 2 Sheets-Sheet 1 vnrenior ,E. Pearson June 17 1924. 1,498,293

1 .E. POIRSON REGULATING TRANSFORMER Filed Aug. 26. 1921 2 ShEGtS-Sheet 2 Patented June 17, 1924.

UNITED STATES PATENT OFFICE.

EUGENE POIRSON, or BELLEVUE, FRANCE, ASSIGNOR T soont'rit DELEGTRO-CHIMIE & DELECTRO-METALLURGIE, or PARIS, rnnnon.

REGULATING TRANSFORMER.

Application filed August 26, 1921.

To all whom it may concern:

Be it known that I, Etienne POIRSON, a citizen of the French Republic, residing at 1 Allee Pompadour, Bellevue, Seine and Oise, 5 France, have invented certain new and useful Improvements in Regulating Transformers, of which the following is a specification.

For controlling the voltage of alternating current circuits, use is generally made of an ordinary static transformer having several contact-pieces connected with varying lengths of the primary or of the secondary. However these arrangements necessitate the interruption of the circuit for effecting each change of contact-piece, and so, if it is de sired to pass, with the circuit closed, from one contact-piece to another, it causes a break ing of the circuit when the contact leaves a contact-piece and before it reaches the following one, or, in cases where the contact pieces are closely arranged, a partial shortcircuit of the winding when the contact reaches the new contact-piece before having left the preceding one. In both cases, the

operation is objectionable, owing to the destructive arcs and to the rapid loading of the circuit.

This invention has for its object the provision of electrical and mechanical arrangements which eliminate these inconveniences and to permit, in practice, the control of the voltage of the circuit. For that purpose, instead of the usual single magnetic circuit, there are provided two magnetic circuits each carrying a primary and a secondary. The primaries are connected in series with the supply circuit and the secondaries are connected in series with the distributing cir- 4O cuit. The multiple contacts are connected with either the two primaries or with the two secondaries or, simultaneously, with both the two primaries and the two secondaries by means of a special switch which is devised in such a manner that (a) On each transformer, the contact does not leave a contact piece before reaching the following one;

(1)) The change from one contact-piece to the next one does not take place simultaneously on the two transformers, but on the contrary, successively and alternately on one and the other.

Serial No. 495,530.

In the accompanying drawings and by Way of example:

Fig. lis a diagrammatical view of the improved transformer, applied to a singlephase alternating current system.

Figs. 2 and 3 respectively illustrate in vertical section and plan view a form of construction of the switch made in accordance with the characteristic features of this inventlon.

Fig. 4 shows, on an enlarged scale, one of the reversible cams under the control of the control lever of the switch.

Referring to the drawing in detail, T and T indicate two magnetic circuits having respectively a primary N N and a secondary n 92 The primaries N N are connected in series with the conductors of the supply circuit U and the secondaries n W, are connected in series with the distributmg circuit to. The collections of current are effected either on the two primaries (Fig. 1) or on the two secondaries, or at the same time on the two primaries and on the two secondaries, this allowing to increase the range of control.

It is obvious that in the case of a polyphase alternating current system, the same arrangements are used for each of the phases.

The changes of contact-pieces for varying the length of the active portions of the windings of the transformers are effected by means of a special multiple contact brush switch, which is devised in such a manner that the two contact brushes, respectively associated with the contact-pieces on each transformer, are mechanically coupled for avoiding the simultaneous shortcircuiting of the two parts of the switch.

The contacts, on these two parts of the switch, and the corresponding contact brushes are, moreover so arranged that:

(a) On each transformer, the contact brush never leaves a contact piece before having reached the following one, so that no actual interruption of the circuit ever takes place;

(b) The change of contact-pieces does not simultaneously occur on both transformers, but on the contrary successively and alternately on one and on the other. Consequently as when one of the transformers is temporarily short-circuited by the contactand c the first. mentioned group being des oil the conducting ring 2.

ignated generally at A and the second mentioned group at A a Thecontact pieces a Z2 a -b -c ,-can be arranged on one andthe same circumterence .(Figs. 2-3). A

Opposite each of'these latter is arranged {a {movable contact element 1. These contact elements are radially arranged on a conducting ring 2 and each is composed 01" a laminated brush 3, resiliently connected by springs' l, with the head 6 of a steel tubular rod 5, said head 6 serving as "an abutment. At the other'end of the rod 'fipdirected towards the center of the switch, is secured a rpller 7 on which can 'acta cam adapted "to push the said rod without friction and th'elatter slides in abronze sleeve 8 secured Asprin'gb is arranged within the tube 5 fa nd isinounted for working by traction; It is combined with two other "springs 10 which siirround'itand work by compression. This resilient system acts for holding the con tacto'r 1 in released position or for suddenly breaking the contact when the outer thrust produced by the cam ceases to act on the corresponding rod 5.

A lon itudinally slotted supporting lever 12 is 'journallefdbn a'shaft and double noting cams '11 are-*pivotally mounted *at 13 in the ends'ofthe-slot o'i'saiid lever, each'cam 11 (Fig. A) controlling group of-c'ontact pieces A and A 7 A cam a'ctua'ting'arm 14 *is mounted on the operatingaxis 15 and is arranged-in the-slot of the lever 12. These cams are constructed so as to progressively and successively push the movable brush carrying elements 1 against the contactpie ces corresponding thereto by means of one or the other of two inclined faces 16 formed on each of the said cams, according to'the directionofm'ovement of the lever 12. Inthe train of the working incline of'each cam are provided two notches 17 and 17 These'notc'hes are formed on thecorre'sp'o'nding end of the lever 12, whilst the inclines 16 'arecon's'tituted, as indicated, by the symi'netrical sides'of the rocking cam 11. These cams 11 are actuatedby fingers 18 carried by 'the'arm lt and projecting in grooves 19 pro- 'videddn the said cams 1'1 (Fig. 4). Two 1 beveled portions are, moreover, formed on either side of the two notches 17, at each of the ends of the lever 12 so as to connect these notches 17 and 17 with the correspending incline 16 of the cam 11.

The operation of the switch is reversible, that is to say a change of the direction of actuation of the arm 14, produces automatically and before any displacement of the lever 12, the shifting or working of the cams 11, so that their opposite inclines 16 project from the leading edge of the lever, with respect to the direction of movement of said lever.

Whatever may. be the direction of rotation of the arm .14, the successive application, in the suitable order, of the brushes 3 on the corresponding contact-pieces will therefore be effected, so that there will never be at the same time two brushes applied on the group of contact pieces a Z) -:0 and two brushes applied on the opposite group d 6 0 the switching taking place alternately on each of these series without any rupture of circuit being produced.

The conducting ring 2 serves as'electric connection beween the two groups of contact-.pieces'and each of thefbrushes 3 is electrically connected to this ring 2'by1neans of flexible conducting cables 21 preventing the formation of destructive arcs when the :sliding contact of each tube 5 in its sleeve 8 takes place.

It will be'noted that upon rotationof the arm 14, lever 12, and cams -1 1, therollers 7 of thesuccessive elements 1 come in'contact, through the medium of the inclines 16, with the two notches 17 and 17 and thenwith the bevelportion20. Beyond this bevel portion,

these rollers aresuddenlyreleased and their resilient system brings them back, thus breaking the contact.

The whole of the cont-actor is preferably a group 'of'contact pieces connected at various points in the "length of'on'e of said Windin'gs, a 'fsecondigroup of'contacti'pieces connected at different points in the length of another of said windings, the :conjt 'actipieces ofthere'spective blocks being circularly arranged, radially movable contacts inovable into engagement 'with'the contact pieces, an adjustable member pivotally mounted at'the axis of the circular series of contact pieces, a cam actuating member mounted eo-axially With the first mentioned member, double acting cams pivotally mounted in the first mentioned member adapted to successively engage and actuate the movable contact members associated with the contact pieces of the respective groups during the rotary movement of the first mentioned member in either direction, means carried by the cam actuating member to move said cams into operative position according to the direction of movement of the first mentioned member, and means on the first mentioned member to engage the movable contact members and maintain the latter in engagement with the contact pieces.

In testimony whereof I have affixed my signature.

EUGENE POIRSON. 

